Obama made a mistake when he was sworn in.

The first time was the Chief Justice's slip of the tongue.

The full text of the oath should be

"I (name) solemnly swear that I will faithfully perform the duties of the President of the United States and do my best to safeguard, protect and defend the Constitution of the United States."

"I [name] solemnly swear that I will faithfully perform my duties as President of the United States of America, and I will do my best to safeguard, protect and defend the Constitution of the United States of America."

Justice said for the first time:

"I, Barack Hussein Obama, solemnly swear that I will faithfully perform the duties of the President of the United States and do my best to safeguard, protect and defend the Constitution of the United States."

"I, Barack Hussein Obama, solemnly swear that I will faithfully perform my duties as President of the United States of America, and I will do my best to safeguard, protect and defend the Constitution of the United States of America." (The position of loyalty is reversed)

Obama knew that the Justice was wrong, so he hesitated, and then the Justice said it again. When he repeated it, the judge himself was too nervous, so he was wrong. He said:

"I, Barack Hussein Obama, solemnly swear that I will faithfully perform the duties of the President of the United States and do my best to safeguard, protect and defend the Constitution of the United States."

"I, Barack Hussein Obama, solemnly swear that I will faithfully serve as President of the United States and I will do my best to safeguard, protect and defend the Constitution of the United States." (Execution disappears)

Obama had to repeat his words, and the result was wrong, but please note that he said the first wrong oath of justice, not the second.

"I, Barack Hussein Obama, solemnly swear that I will faithfully perform the duties of the President of the United States and do my best to safeguard, protect and defend the Constitution of the United States."

"I, Barack Hussein Obama, solemnly swear that I will faithfully perform my duties as President of the United States of America, and I will do my best to safeguard, protect and defend the Constitution of the United States of America." (The position of loyalty is reversed)